Can you keep chocolate candy from getting soft after making it?

I make a chocolate morsel (1 cup) and peanut morsel (10 oz. bag) and 10 oz. Spanish peanuts candy. I melt the chocolate and peanut morsels and then stir in the peanuts. It then gets dropped by teaspoons onto wax paper to harden. I refrigerate the candy after several hours to totally harden the chocolate.

When I serve the candy, if it's out of the refrigerator for a while, the chocolate gets slightly soft. It doesn't melt, just comes off on the fingers a bit. Is there anything that can be added to the chocolate when melting it to prevent this?